Furnace.



No. 6363137. Patented Oct. 3|. I899.

w. P. GBATH.

FURNACE.

(Application filed Nov. 88. 1898.) (No Model.)

T I G l- FIEL E .llmil g 6 I UNITED STATES ATEN'r FFICE.

VALTER P. GRATH, OF ST. LOUIS, MISSOURI.

FURNACE;

SPECIFICATION forming part of Letters Patent No. 636,037, dated October31, 1899.

I Application filed November 23, 1898. Serial No. 697,282. (No model.)

To all whom it-may concern:

Be it known that I, WALTER P. GRATH, a citizen of the United States ofAmerica, and a resident of the city of St. Louis, in the State ofMissouri, have invented a certain new and useful Furnace, of which thefollowing is a specification.

My invention relates to furnaces, andhas for its principal objects toutilize coal-slack as fuel and to avoid the generation of dense cloudsof smoke.

To these ends my invention consists in providing the combustion-chamberof the furnace with shelves or platforms for supporting the fresh slackand in so arranging the draft-fiues that such slack will be thoroughlycoked before it is applied to the fire-grate.

In the accompanying drawings, which form part of this specification,Figure 1 is a front elevation of a furnace embodying my invention. Fig.2 is a cross-section thereof on the line 2 2 of Fig. 3, and Fig. 3 is ahorizontal section on the planes indicated by the line 3 3 of Fig. 1. v

. Like symbols refer to like parts wherever they occur.

The outer walls 1 and roof of my furnace are built in any usual way ofbrick or other suitable material to inclose the grate 2 and thecombustion-chamber. From one or both of the side walls shelves 3 extendhorizontally.

to form brackets or platforms, which are located a convenient distanceabove the grate. The inner edges of these shelves or platforms arepreferably supported on walls 4, having openings therein, or on columnsarranged to leave spaces between them. Such columns or walls thusconstitute a fire-box or convenient means for confining the fuel, butallow the products of combustion to enter and circulate freely in thespaces or flues under the shelves, which spaces are in effect lateralextensions of the combustion-chamber. As the shelves are imperforate,the spaces in the combustion-chamber above the shelves are out off fromthe supply of air and constitute coking-chambers, which are continuouswith the combustion chamber. The outer rear wall is protected by afire-wall 5, having an opening 6 in its upper middle portion and abuilding a fire of any suitable fuel upon the grate in the fire-box, andthe slack to be used for fuel is piled on the two shelves or platformsat the sides. The air necessary for combustion is supplied through theash-pit and grate, and the main volume of the products of combustionpass out through the openingin the fire-wall, whence they pass throughthe opening in the outer rear wall into the kiln, boiler, or otherplace. A portion of the products of combustion, however, pass throughthe opening in the sides of the firebox into the extension or finesbelow the respective coking-cliambers,and thencethrough the openings inthe inner rear wall into the rear flue, and thence out through theopening 8 in the outer rear wall along with the main volume, which hadtaken the more direct course. By this arrangement the slack in thecoking-chambers is not only exposed above to the direct heat in thefire-box, but as the shelves or platforms which constitute the bottom ofthe coking-chambers are the tops of the side fiues orextensions of thecombustion-chamber as well, such slack is exposed below to the heat inthe flues or chamber. Thus all portions of the slack are sufficientlyheated to become thoroughly coked, and the hot gases generated therefromare driven off into the draft of air coming up through the grate and areconsumed. When new fuel is required for the fire-box, the coke thusformed is raked oif the side shelves in one or more large masses ontothe grate and a supply offresh slack is shoveled into thecoking-chambers.

While the construction represented in the drawings is the best form ofmy device, my invention admits of considerable modification. Forinstance, instead of having one fire-box between two shelves there maybe only one shelf extending from the wall or there may be one centralplatform between two fireboxes, and in either case satisfactory resultsare obtained by providing openings in the side or sides of the fire-boxfor the free radiation of heat and circulation of products of combustionwithout providing any special outlet therefrom. So, also, where no innerwalls are used for limiting the fuel or where the openings therein aresufficiently large no special outlet opening need be made under theshelves or platforms.

My furnace is specially designed for burning coal-slack and isapplicable for heating kilns, boilers, and other furnace uses. Its mostimportant advantages are that it thoroughly cokes all the slack beforeburning the same, whereby the maximum heating value of the fuel isobtained, smoking is avoided, and the fire easily regulated.

Another important advantage is that part of the gases generated in thecoking-chambers and escaping therefrom are carried along in the draftfor a considerable distance before ignition, whereby the heat may bedistributed more evenly through the kiln.

\Vhat I claim is 1. A furnace comprising outer walls inclosing a grateand a combustion-chamber and having a raised imperforate platformarranged under the roof of the combustionchamber and extendinghorizontally from a wall thereof so that a mass thereon may be pushedoff onto said grate, the space beneath said platform being open to theproducts of combustion, and the space above said platform beingcontinuous with the combustionchamber and cut off from the supply ofair, substantially as and for the purpose set forth.

2. A furnace comprising outer walls, a firebox therein havingaseparatewall with openings therein, and ashelf extending from said fire-box wallto the outer wall, said furnace being provided with a flue for the maindraft from the combustion-chamber and a secondary outlet-fluecommunicating with the chamber beneath said shelf, substantially as andfor the purpose set forth.

3. A furnace comprising outer walls, a firebox therein having separateside walls provided with outlet-openings,a platform on each side of thefire-box extending from the top of the fire-box wall to the outer wall,said furnace being provided with a main-draft flue opening into the rearend of the combustionchamber and secondary-draft fiues communicatingwith the space beneath the side platforms, substantially as and for thepurpose set forth.

4. A furnace comprising outer walls, a firebox therein having a firewallat the rear thereof provided with the main outlet-open ing for theproducts of combustion, and having separate side walls provided withsecondary outlet-openings, and platforms extending from the side wallsof the fire-box to the outer walls, the chambers below said platformscommunicating with the space back of the firewall, the outlet-openingfor the products of combustion being located in the rear wall,substantially as and for the purpose set forth.

Signed at St. Louis, Missouri, this 19th day of November, 1898.

\VALTER P. GRATII.

In presence of JOHN B. RENO, JAMES A. CARR.

